Radiospeaker



A.A.KENT

RADIO SPEAKER March 3, 1931.

Filed y 26, 1925 2 Sheets-Sheet 1 IMVEN TOR A TTORNE Y A. A. KENT RADIO SPEAKER March 3, 1931.

Filed ma ize, 1925 2 Sheets-Sheet 2 v INVENTOR By M M M 1 ATTORNEY Patented Mar. 3, 1931 ARTHUBIATWIATER iinn'rpon ABDMOREZ, r EnNsrnvAnIA 1 namosrnakna with-means carried by the, frame or yoke for flexing the pole piecesto effect adjustment 15 of the distance or air'gapibetween' them and :7

the coo-acting vibrating armature fixed at its one end to one side of the yoke or frame and extending preferably transversely to the iongit-udinal extent-of the polepieoes.

Further in accordance withmy invention, the adjustment ofothe pole pieces with respect to the vibrat-i'le armature is eflected' by structure of such character that as thepole pieces are defiected towards the armature,"the armas 25 turesimultaneouslyrecedes fromthe pole pieces, but to lesser extent. a 7 Further in accordance with m'yinvention, the air-vibrating diaphragm or tympanum, of paper, metal or other suitable material, preferably of large area or diameter and preferably conical, is secured fixedly either direct- 1y to the vibratile member of the magnetsystem'or-upon a'member which inturn is directly secured to the vibrating member ofthe ,m'agnet system; further;'inuaccordance with myinveution, a stander support forthe'instrument as a'whole comprlses a support to \vlnchthe magnet system is secured, and the tympauum or diaphragm is carried by such 4 system and particularly the vib'ratile element thereof. 7 i r Further in acoo'rdancefwith my invention, the diaphragm or tyinpanum is secured Q1 or audio frequency amplifier as utilized comconfined only at or adjacent its cente'n'and at "its periphery-is'entirely free,="unsupported- 7 yings in"circuit. As usual, the two windings and undamped Further in accordance with myi'n'vention, there may be provided for the diaphragm-or j tympanum a'shieldor guard surrounding but Application filed May 26,

be had to the support through the medium of thenlagnetspaced from its periphery to leaveit-unsupi Pric 1 ported'and-free to vibrate thereat and to protect'itfrom contact with other objects.

My invention resides in apparatus of the character hereinafter described and claimed. For an illustration-of one ofthe various forms my invention may take, reference is to accompanying drawing, in which: I I i Figure 1 is a front elevational view of structure embodying my invention, with apor'tion of the diaphragm cut away."

1Figu2' is a vertical sectional view',partly in side elevation, of-structure shown in Fig. 1. Fig. 3 is a fragmentary vertical cross sec tional view, partly 'irrisidexelevation, on the line 8-.3, Fig. 1, illustrating structure of the magnet system.

Fig. 4 is a fragmentary horizontal sect-ion,-

al view, partly in plan, taken on the line 4 Fig. 1,uillustrating structure of the magnet I system;

Fig. 5 is a slde elevational view,.partly in vertical section, illustrating the-application ofa housing or-guard. 7 Y 1 Referring tothe drawings, I is a base or stand, to which is secured by screw Q'a bracket member 3, to which is secured theupwardly extending supporting memberf l, to whose up per'end is secured by screws theopen substantially rectangular frame or yoke ,6 of the magnet system, suitable spacing mcmhers 7 being interposed between the yoke or frame .6 "and the support 4 through holes in which the screws 5 extend and have applied thereto on the rearof the support 4 theuuts 8. Secured to the yoke or framed by the same screws Sure the ii'm'ardly 'extendingpoie pieces 9, between whose ends isleft on air gap. Surrounding thepole piecesn9 are the e w1nd1ngsor .co1ls C traversed-by the 'vo1ce-- or sound-represent1ng current, such as (EXlStS,

for example, in the anode, circuit of a detector conductors c, 0 serving to connect the windmaguetic'fieldacting upon the-vibratile menu-" nionly in radio receiving circuits, the flexible; V

her 10. The yoke 6 is preferably permanently magnetized, having poles of opposite signs at opposite ends thereof adjacent the points of attachment of the soft iron or steel pole pieces 9, 9, whereby at the inner and adjacent ends of the pole-pieces 9 are exhibited opposing north and south magnetic poles.

The vibratile member or armature of the magnetic system comprises the soft iron or steel bar or reed 10 secured by screw 11 to the yoke or frame 6 substantially midway between the points of attachment thereto of the pole pieces 9, or at a substantially neutral magnetic point 'or region of the frame .6. There preferably intervenes between the armature 10 and the frame 6 a washer 12, for

spacingthe lower or free end of-the armature 1O fromthc pole pieces 9, and serving also as an abutment for the armature about which it may flex or bend under the influence of the sourld-re n-esenting current V Extendingsubstantially parallel'with the arn iatn 10, but out-he opposite side of the frame 6 therefrom, is the substantially rigid bar secured to the yoke 6 by the screw 11.

Adjacentthe inner or free end of the bar 13, which may be of'soft iron or steel or other suitable metahthere is threaded-therethrough the adjusting screw. 14 of brass, locked by the nut 15, and having a flat end engaging the polepieces an) align them and to. flex them to adjust the air gap between them and the armature 1 0. 1

Threaded into or otherwise fixedly secured to the vibratile member 10 is the pin or rod 16, to which is fixedly secured the. air-vibrating member, diaphragm or tympanum..

The tympanum or diaphragm 17, in the form of a cone, and of relatively large diameter, preferably upwards of six inches, is pro-' vided exteriorly and interiorly at its apex with the metal reinforcing conical members 18 and 19, to which is secured the bushing 20, through which extends the rod or'pin 16, against which set the screw 21 threaded in the bushing 20, whereby thecone or diaphragm is fixedly secured and supported solelv by-the vibratile member or armature 10,

through which and the magnet system the diaphragm or cone is supported upon the bracket or upporting member 4.

While, as'indicated in Fig. 2, the cone may be so placed upon the rod 16 that the support at and the magnet system are disposed within the cone, it will be understood that, as indicated inidot-ted lines, the diaphragm or cone may be reversely-placed upon the pin 16, particularly sincev the periphery of the dia-i phragm or cone is left entirely unsupported and free to vibrate:

In operation, the lowerorfree end of the armature 10 isisuita-bly ispaceduby air gap from and'bridg es the inner ends ofthepole.

pieces ,9, which exertupon thearmature:'10a" m a gnet-ie attraction-which is -var ied in;acc ord- '1:

ance with the voiceor sound-representing current, w1th the result that the member 10 and with an amplitude depending upon the amplitude of the current.' The vibrations of the armature 10 are communicated to the conical tympanum through the rod orpin 16, if utilized, or directlyito the tympanum if the latter is directly or immediately secured upon the armature 1( The cone 17 vibrates the cone is unrestricted throughout and free ii to vibrate at its extreme periphery at the frequency and with the amplitude of vibrations transmittedthrough. the cone from its axis or center, whereat-only it is secured or fixedato and comprehended'iin the vibratory system comprising in addition the vvibratory armature 10. y

As indicated, the point of attachment of the cone 17 or its supporting pin or rod 16 to thearmatu-re 10 may be disposed to some extent nearer the supporting screw :11 than the center of the polepiecesQ. Howelver,

such point of attachment may be {otherwise 'located,,t-o accord with the diameter orarea ofth'e diaphragm or cone.

To effect adjustment of the distance or air gap between the ends of the pole pieces 9an d the armature 10, the adjusting screw 14k is rotated, when the lock nut 15 is loosened, inward movement of the'screw 14, which at its flat end engages both'po'le pieces 9 and serves to aligntheir lateral surfaces, causing fiexure of the pole pieces toward the left, 1g. 3,-thereact on also flexing the frame or yoke b, and caus ng the free or lower end of the armature 10 simultaneously to move away from the pole pieces '9, but to lesser extent than the ends of the pole pieces 9 are forced toward the armature 10, whereby in effect the resultant adjustment is fine ornice,

because of the differential effect procured.

T shield or guard the cone or diaphragm l'f fwliic'h may be constituted of paper or of thin sheetinetal as aluminum, brass, etc., there. may be provided the housing, shield or guard'structure 22, 5. extending around th per phery, o the aphra mr i s and .U f, l g e s e t l er or ths de -b h ,periph y,but- WQNS llbi i l i ially space theref om to permit "free vibration of the 'cone throughout and at iit-s per-iphery, The shie d oe as t-rupt re, may. b of met me tl g the se eral s n .aextemh:

ma y 1 vibrates in accord with the current variations ating member operated by said vibratile bar.

2. A telephone magnet system comprising a permanently magnetized and circumferentially continuous magnetframe, pole pieces therefor extending from opposite sides of said frame and having their inner ends spaced from each other, windings on said pole pieces traversed by sourid-representing current, and a vibratile ai'i'nature bar secured adjacent its one end to said magnet frame and having its free end disposed adjacent the inner ends of said pole pieces and bridging the gap'be tween them.

3. A telephone magnet system comprising a. magnet frame, pole pieces therefor, means carried ,by said frame and engaging said pole pieces to effect their alignment With each other, and a Vibratile armature reed co-actingwitli said pole pieces.

4. A telephone magnet system comprising amagnet frame, flexible pole pieces therefor, a vibratile reed-armature co-acting with.

saidpole pieces, and an adjustable member carried by'said frame engaging said pole pieces and to flex them with respect tosaid armature.

5. A telephone magnet system comprising a magnet frame, pole pieces therefor, a vie bratile reedfarmature co-acting with said pole pieces, a bar secured to; said magnet frame and extending toward said pole pieces, and an adjusting screw carried by said bar and engaging said pole pieces to effect their alignment with each other.

6. A telephone magnet system comprising a magnet frame, flexible polepieces therefor, avibratile 1G(3(l1l'1)'1t1t111' co-acting with said pole pieces, a bar secured to said magnet frame and extending toward said pole pieces,

and an adjusting screw carried by said bar:

and engaging said pole pieces to effect their alignment with each other and'to flex them 7 with respect tosaid armature. I

7 A telephone magnet system comprising a magnet frame, flex'iblepole pieces therefor, 1

a vibratile armature carried by saidframe and co-acting with said pole pieces, and an adjusting member carried by said frame engaging said pole pieces to flex them toward said armature and reacting through said frame to cause said armature to recede from, *iphragin: at- :its apex, athe base of e fligtile armature bar having its free end'disdisposed entirely free and unconfinediii saidt" means for adjustahly suppdrtiilgsa said pole pieces to lesser extent than T's'afid pole I pieces are flexed-toward said armature;

' 8. A telephone ni'agiiet system comprising a magnet frame, pole pieces therefor, a vibra tile armature bar'secured-adj sce e its one end to said ma net frameandhaving "its ee' end? disposed adjacent said polejpieces, l a I second bar secured to saidinagn'et frame ad? I ja'cent' the attachmentthere'to of said arma ture bar, and an adjusting screw carried by said secdnd named jb'ar' engaging s'aidz'pole pieces; to' effect their" alignment with each i 9; A telephone magnet system comprising. a magnet frame, flexible pole pieces therefor,

a vibratile armature bar-' liaving its free'en'd disposed adjacent ,p'olepiece's', asecond 7 bar, means common; to said bars for securing.

them to said magnet-frame,- and an adjusting screw carried'by said second namedbar 85 and engagingsaid pole p eces to f1eX" them;

:10; A telephone magnet system" comprising magnet frame, pole pieces secured to the same face of said magnet frame, a vibraposed adjacent saidp'ole' pieces, meanslfor securing said'a'rma'turebar'adjacent its other 'end to said magnet iframe' onsaidi-face thereof, and means for spacing said other end of magnet frame;

said armature bar from isaidfaceofasaid j a supporting member, a magnet frame; pole pieces therefor, EL' 'VIbIEI SI IG armature.= coact- 'ing with said pole p1ece's,zand meanscom prising a plurality of screWs al'lcommonfo' said supporting member; magnet frame'and pole pieces for holding tliem'in'assembled relations i ,3

v '12 I teleph'oneymagnet system 1 comprising a supporting member, a magnet frame, spacing .members' interposedibetween said supporting memberand framefpole pieces 5 for said magnet frame, a vibr atile, armature co-acting With saicl;;poler'pief0es, and means comprising a plnralitywof members trav- 1 er'sing'said spacinglincmbers' and common to, said supporting member, magnet, frame and poleqpieces for *holding thcm niaas sembled relation 1 1 i 1 s a support carried thercby,saidsupport hay ,ing ail-open. peripheral bea-di'n g,.afilarge direct acting-vibratory diaphragm of conoidal form beading, saiddiaphiagQm being of non-me tallic mater1al .a sound;{reproducinganstrug 'inentality carried bysaid support; and means operatively con nectingzsaid instrumentali-ty w th the apexiof said diaphragm. 14.. The combination "with-'-areproducer 13. A sounda -nplifiei comprising astand,

phragm being entirely :free and unconfined, said supportingmeans also communicating vibrations from the reproducer to the diaphragm. a

15. 3 A telephone magnet system comprising a permanently magnetized and circumferen- V-tial-ly oontinuousvmagnet frame, a vibratile site sides of said frame and. substantially at right angles to said vibratile armature bar which bridges a gap between spaced inner ends. of saidpole pieces.

"17;, iA sou-nd'amplifier comprising a stand, a support carried thereby, said support havingan open peripheral beading, a large direct acting vibratory diaphragm of conoidal form loosely disposed in said beading, said diaphragm belng of non-metallic material, a

sound reproducing instrumentality carried "by sald support, and means operatively connectingsaid instrumentality With the apex of said diaphragm.

18; The combination with a reproducer actuated by current vibrations produced by sound, Of a hollow conoidal diaphragm,

means for adjustably supporting saidgdiaphragm at its apex ina'vertical plane, the base of the. diaphragm being entirely free and unconfined, said supportingimeansalso communicating vlbrations from the reproducer to thediaphram.

'19. A sound amplihcr comprising a stand,

an arm raised from said stand, a reproducing instrumentality fixed at the end of said arm, and an amplifying diaphragm supported in "a vertical plane and actuated. directly'by said instrlunentality, said rdiaphrag'm being wholly tree and nnrestrained.

2(). A sound amplifier compi'isinga stand, an arm extending from said stand, a sound reproducing device supported by said arn1, a rod supportedby said sound reproducing-de- I vice, and "a co'noi'dal diaphragm operatively fixed at its apex on said-rod tov'be supported and vibrated thereby, said diaphragm being otherwise unconfined. I

21.}An amplifying telephone comprising r armature, and a rotatable adjusting member for adjusting the air gap between said pole pieces and armature, said member having means disposed .Within the control diaphragm for manually operating said mem ber.

ARTHUR .ATWATER KENT.

asupport,a'telephonemagnetsystemcarried said supportan'd coniprising 'a vibratilearmaturejand olepieces, ,a conical diaphra gm of large diameter vibratedsbyi said CERTIFICATE OF CORRECTION. 7 Patent No. 1,794,855. Granted Merch 1931, to ARTHUR A'IWATER KENT.

, it is hereby certified that error appears in the printed specificationofthe above numbered patent requiring Correction as follows: Page 4, line 69, claim 21, for the word "control" read conical; and that the said 'Letters Patentshould be read with this correction therein that the same may conform to the record of the case in the Patent Office. e

' Signed ,and sealed this 31st day'of March, A. D. 1931.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

